ترغب بنشر مسار تعليمي؟ اضغط هنا

Filter Quotients and Non-Presentable $(infty,1)$-Toposes

54   0   0.0 ( 0 )
 نشر من قبل Nima Rasekh
 تاريخ النشر 2020
  مجال البحث
والبحث باللغة English
 تأليف Nima Rasekh




اسأل ChatGPT حول البحث

We define filter quotients of $(infty,1)$-categories and prove that filter quotients preserve the structure of an elementary $(infty,1)$-topos and in particular lift the filter quotient of the underlying elementary topos. We then specialize to the case of filter products of $(infty,1)$-categories and prove a characterization theorem for equivalences in a filter product. Then we use filter products to construct a large class of elementary $(infty,1)$-toposes that are not Grothendieck $(infty,1)$-toposes. Moreover, we give one detailed example for the interested reader who would like to see how we can construct such an $(infty,1)$-category, but would prefer to avoid the technicalities regarding filters.



قيم البحث

اقرأ أيضاً

The Bourbaki-Witt principle states that any progressive map on a chain-complete poset has a fixed point above every point. It is provable classically, but not intuitionistically. We study this and related principles in an intuitionistic setting. Am ong other things, we show that Bourbaki-Witt fails exactly when the trichotomous ordinals form a set, but does not imply that fixed points can always be found by transfinite iteration. Meanwhile, on the side of models, we see that the principle fails in realisability toposes, and does not hold in the free topos, but does hold in all cocomplete toposes.
Are all subcategories of locally finitely presentable categories that are closed under limits and $lambda$-filtered colimits also locally presentable? For full subcategories the answer is affirmative. Makkai and Pitts proved that in the case $lambda= aleph_0$ the answer is affirmative also for all iso-full subcategories, emph{i.thinspace e.}, those containing with every pair of objects all isomorphisms between them. We discuss a possible generalization of this from $aleph_0$ to an arbitrary $lambda$.
108 - Bas Spitters 2013
In the (covariant) topos approach to quantum theory by Heunen, Landsman and Spitters, one associates to each unital C*-algebra, A, a topos T(A) of sheaves on a locale and a commutative C*-algebra, a, within that topos. The Gelfand spectrum of a is a locale S in this topos, which is equivalent to a bundle over the base locale. We further develop this external presentation of the locale S, by noting that the construction of the Gelfand spectrum in a general topos can be described using geometric logic. As a consequence, the spectrum, seen as a bundle, is computed fibrewise. As a by-product of the geometricity of Gelfand spectra, we find an explicit external description of the spectrum whenever the topos is a functor category. As an intermediate result we show that locally perfect maps compose, so that the externalization of a locally compact locale in a topos of sheaves over a locally compact locale is locally compact, too.
We use Luries symmetric monoidal envelope functor to give two new descriptions of $infty$-operads: as certain symmetric monoidal $infty$-categories whose underlying symmetric monoidal $infty$-groupoids are free, and as certain symmetric monoidal $inf ty$-categories equipped with a symmetric monoidal functor to finite sets (with disjoint union as tensor product). The latter leads to a third description of $infty$-operads, as a localization of a presheaf $infty$-category, and we use this to give a simple proof of the equivalence between Luries and Barwicks models for $infty$-operads.
Adjoint functor theorems give necessary and sufficient conditions for a functor to admit an adjoint. In this paper we prove general adjoint functor theorems for functors between $infty$-categories. One of our main results is an $infty$-categorical ge neralization of Freyds classical General Adjoint Functor Theorem. As an application of this result, we recover Luries adjoint functor theorems for presentable $infty$-categories. We also discuss the comparison between adjunctions of $infty$-categories and homotopy adjunctions, and give a treatment of Brown representability for $infty$-categories based on Hellers purely categorical formulation of the classical Brown representability theorem.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا